Hand morphology, manipulation, and tool use in Neandertals and early modern humans of the Near East.

Abstract

Between 140,000 and 50,000 years ago, both Neandertals and early modern humans periodically inhabited the coastal woodlands and inland steppe of the Near East. The archeological remnants of the behavior of these two groups—mostly in the form of stone tools and animal bones—are so similar that were it not for the fact that both groups occasionally buried their dead in the caves in which they lived, we would not have known that they derived from more than one population. Although morphologically and taxonomically distinct, both types of human are associated with Middle Paleolithic (Mousterian) stone-tool assemblages that cannot be differentiated clearly on the basis of technological and formal typological attributes (1, 2). But although the archeological record indicates behavioral similarity, and by inference adaptive similarity, between Neandertals and early modern humans at this time, functional morphological studies of the human skeletons suggest quite a different story. Detailed study of parts of the skeleton that alter their material and geometric properties during life in response to activity or that show degenerative changes from wear and tear suggest important behavioral differences between these groups (3, 4). This situation raises perplexing questions. If both tool assemblages and the malleable aspects of the skeletons of the humans who made, used, and discarded those tools are monitoring prehistoric behavior (5), why do these two data sets produce such contrasting interpretations of that behavior? And if behavioral contrasts did exist, did these contrasts serve to give one group a competitive advantage? This later question is important, because many see the Near Eastern early modern humans as the source population from which modern humans migrated into Europe approximately 36,000 years ago—leading to the extinction of the Neandertals soon after. Evolutionary models that posit a single center of origins for modern humans (such as Africa) with …